Effects of Resistance Training on Strength, Physical Function and Quality of Life in Older Adults

Abstract

Muscle weakness can limit older adults’ ability to perform daily activities and could negatively affect quality of life (QOL). Resistance training using loads of approximately 65-75% of one repetition maximum (1-RM) are recommended to improve strength in older adults, however, the use of low-load (30% 1-RM) blood flow restricted (BFR) resistance training may result in similar strength gains. PURPOSE: To compare strength, physical function and QOL adaptations following 12-weeks of high-load (HL) and BFR training in older adults at risk of mobility limitations. METHODS: Thirty-six male and female older adults (76.0+7.6 years; 26.6+3.3 kg·m-2) who possessed low knee extension muscle strength placing them at risk of developing mobility limitations participated. They were randomly assigned to perform twice weekly sessions of HL (70% 1-RM), BFR (30% 1-RM coupled with a vascular restriction of 1.5 times systolic blood pressure at the proximal thigh) or attention control (CON) exercise for 12 weeks. HL and BFR groups engaged in three sets of leg extension (LE), leg press, and leg curl resistance training to muscular failure. The CON group performed three sets of light upper body resistance and flexibility training that was not expected to result in muscle adaptations. LE 1-RM, isometric strength, strength-to-weight (STW) ratio, Short Physical Performance Battery (SPPB), 400 m walking speed and four domains of QOL via survey were assessed before, midway and after 12 weeks of training. RESULTS: HL and BFR groups had increases of 8-56% in LE 1-RM, isometric strength and STW ratio within 6-weeks of training and maintained these changes at 12-weeks while the CON group had no changes (time x group P.05). Walking speed and SPPB improved 3% and 5%, respectively among all groups (time main effect P>.05). There were no changes in QOL in any group (time x group P>.05). CONCLUSION: HL and BFR training improves muscle strength similarly in older adults at risk of mobility limitations, suggesting BFR exercise is a viable exercise modality. Enhanced physical function without changes in QOL was seen in all groups. The impact of increased strength on physical function should be further evaluated with additional tests of daily activities. Supported by NIH grant 1R15 A6040700-01A1.